[Closed] brake return sprng issue

hi been away for a while but got hold of a tandem that needs some work and want to replace the normal canti's for some v-brakes. Now the frame only has one pin for the brake return pin instead of the three i'm used to and the deore v-brakes out of my drawer fit but there isn't enough adjustment for the spring to be effective. Is there any version of any brake that might offer more adjustment or a way of ading more pins to give the return spring something to bite onto? the frame is more racer than mountain and so the gap between the vees is prob smaller than normal but would prefer to run vees. HELP!!!